Selection of materials for the prosthetic liner using coconut water composite as a substitute for EVA

This research was conducted to analyze coconut water composite as a material that can substitute EVA for prosthetic liner products. According to data from the Ministry of Health of the Republic of Indonesia, there are 2.45% of people with disabilities from the total population in Indonesia. From this percentage, there are 10.26% of people with walking disabilities. Some people with disabilities walk using prosthetic leg as a tool for activities. Many prosthetic users in Indonesia use EVA liners as a medium to reduce pressure between the stump and the socket. EVA is used as a liner product because it can reduce the pain of prosthetic users during activities. EVA is a material made from petroleum. Excessive use of EVA will cause environmental pollution. It is hoped that coconut water composites can be a solution to this problem. According to BPS in 2018, the area of coconut plantations in Indonesia reached 3,417,951 ha. Coconut water is used as the basic material for making composites. Composite research was conducted to determine the physical properties through tensile tests to determine the stress and strain of the material and the method of manufacture of the composite. The factors used in the manufacture of composites are temperature, pressure, and pressing time. The composite tensile strength test was carried out according to the ASTM D638 standard. This study uses a factorial design model to determine the significance value of each combination of factorial and factorial using the ANOVA comparison model. The result of the highest tensile stress from research on coconut water composite is 47.20 MPa. The results of the tensile test showed that the coconut water composite treatment had a higher stress value than EVA.